This invention relates to A.C. electric motors and, in particular, to improvements of stators of A.C. electric motors.
In known A.C. electric motors such as induction motors and synchronous motors, a stator must be formed with slots in its cylindrical surface confronting the rotary surface of a rotor with a magnetic gap therebetween, in which slots armature windings are disposed and electrically insulated. Because poor formation of slots and poor disposition of windings cause unevenness in rotation of the motor, much care and long time are disadvantageously taken to produce the stator.
Rotating speed of the known A.C. electric motor can be controlled by adjusting the applied A.C. voltage, but this means that the rotating speed changes by variations of the applied A.C. voltage.